Separating system



Dec. 20, 1938. c. w. BOAG SEPARATING SYSTEM Filed Oct. 24, 1936 i "rToRNEY Patented Dec. 20, 1938 UNITED STATES SEPARATING SYSTEM Charles Wesley Boag, Milwaukee, Wis., assignor to The Hell 00., Milwaukee, Wis, a corporation of Wisconsin Application October 24, 1936, Serial No. 107,395

2 Claims.

The present invention relates in general to improvements in the art of treating commodities such as forage, and relates more specifically to an improved system for cooling, grading and for 5 separating refuse from forage or the like which is being conveyed by air from a source of treatment such as a drier.

Generally defined, an object of my present invention is to provide an improved system for automatically and effectively conditioning the product delivered from a hay drier or the like, so that the commodity will be ready for final reduction and merchandizing,

Remarkable results have recently been attained in the production of food for poultry and the like, by passing forage such as alfalfa immediately after'it has been cut, through a rotary drier wherein the material is simultaneously effectively dried and transported by a mixture of air and hot gases of combustion. The mixture of forage and gas is ordinarily drawn through the drying drum by means of a suction fan, and is delivered by the main fan through a cyclone or similar separator from whence the separated material has heretofore ordinarily been discharged directly either to bags and other containers, or to a disintegrating mill for final reduction. I have found that the dry material thus delivered from the primary separator is still quite hot and frequently contains refuse such as stones or pieces of metal, the presence of which in the final product is extremely obj ectionable. When the dried commodity is passed through a rotary impact pulverizer such as is ordinarily used for final disintegration, it is further heated by the impact and abrasive actions, and the presenceof foreign objects such as stones and metal may produce sparks which will ignite the dry forage in the reducing mill. It is therefore very desirable to cool the product as much as possible after it leaves the initial separator in order to prevent subsequent excessive heating, and to also remove the refuse therefrom, prior to final disintegration and packaging or bagging 5 thereof.

The present invention therefore contemplates provision of a simple, compact and efiicient system for simultaneously cooling the forage and for automatically removing objectionable refuse from the wholesome product, thereby placing the latter in better condition for further treatment and final merchandizing.

Another specific object of my present inven-,

tion is to provide simple and readily manipulable instrumentalities for controlling the distribution of material delivered from a forage drying system or the like, and for separating such materials into selective grades if desired.

A further specific object of this invention is to provide an improved cooling system wherein the temperature of the material is quickly and effectively reduced by substituting an abundance of fresh air for the hot drying gases previously used as a conveying medium for the particles during the drying operation.

Still another specific object of my present invention is the'provision of an improved conduit assemblage for conducting a forage laden stream of air from one place to another so as to automatically remove heavy and undesirably large particles of refuse or the like from finer grades of the material.

An additional specific object of the invention is to provide an improved cooling and separating system for granular and fibrous material, m which may be installed and operated at moderate cost, and which is dependable in actual operation.

These and other objects and advantages will be apparent from the following detailed description.

A clear conception of the several features constituting the present improvement, and of the mode of operating the improved cooling and separating system, may be had by referring to 30 the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a somewhat diagrammatic side eleva- 35 tion of a forage drying system having the improved cooler and separator embodied therein;

Fig. 2 is an enlarged central vertical section through a fragment of the improved cooling and separating system, showing the same in action; 40

and

Fig. 3 is a similarly enlarged transverse vertical section through the cooler and separator of Fig. 2, the section being taken along the line 3-3. 46

While the invention has been illustrated as being applied to a specific type of drying system especially adapted for the treatment of forage such as alfalfa, it is not the intent to thereby unnecessarily restrict the scope.

' Referring to the drawing, the forage drying system shown in Fig. 1 by way of illustration, comprises in general a relatively large and elongated drier drum 5 rotatably supported upon a main foundation 6 by means of rollers I; a I 4 main suction or exhaust fan 8 having an axial inlet pipe 9 communicating directly with the delivery end of the drum and also having a tangential peripheral discharge pipe l0 leading into the upper end of a centrifugal separator I I; an auxiliary suction fan l2 having an axial inclined inlet duct or pipe l3 extending downwardly at an angle and beneath the lower material delivery end I4 of the main separator ii; an open hopper i5 disposed beneath the separator end I and having a lower end IS in open communication with the open lower end I! of the pipe l3; a shut-off gate l8 interposed within the pipe l3 between the hopper l5 and the fan l2; a second centrifugal separator l9 having an upper inlet pipe 20 which also constitutes the peripheral discharge conduit of the fan l2; and a two-way final material delivery conduit 2| associated with the lower discharge end of the second separator l9.

The drier drum 5 has a series of internal material showering flights and is provided with a circuitous passage through which the forage is normally transported by hot gases and is simultaneously subjected to drying action, in a well known manner, and the mixture of hot gas and material is constantly withdrawn from the interior of the revolving drum 5 through the pipe 9 and is delivered to the initial separator ii through the pipe ill. The main separator H is of the well known cyclone type, and is adapted to continuously separate the solid material from the gases, the granular material 22 being delivered by gravity toward the lower discharge end I and the gases being discharged through a central upper outlet 23. The drier drum 5, fan 8 and separator l i are all of well known construction and operation, and therefore require no further detailed disclosure and description.

The cooling and separating assembly constituting the present improvement and comprising the inclined pipe l3, the hopper l5 and the gate I 8, is shown in detail in Figs. 2 and 3, and may be supported from the floor 24 by frame members 25. The hopper l5 may be swingably suspended from the lower end portion of the pipe [3 by means of a hinge 26, and the upper enlarged open end of the hopper i5 is preferably spaced some distance from the delivery end ll of the main separator I I so that the dried forage 22 may drop freely into the hopper by gravity, as illustrated in Figs. 1 and 2. As shown, the hopper I5 is square in transverse cross-section, but it may be round, and the lower constricted end l6 of the hopper should be in open communication with the pipe l3 at all times. The open lowermost end of the pipe I3 should also be unobstructed for free admission of abundant quantities of cooling air and for the discharge of abnormally heavy particles 21 such as stones, pieces of metal or unusually large stems; and a coarse screen 28 may be inserted across the interior of the pipe l3 just beyond the hopper end IS. The shut-oil gate I8 is slidably adjustable between guides 29 and is adapted to be frictionally retained by these guides in any desired position of adjustment, so that the pipe l3 may be more or less restricted in cross-section by the gate i8, or it may beclosed off entirely.

The secondary fan I2 and separator l9 are likewise of well known construction, and the pipe i3 preferably approaches the fan inlet at an inclination but without abrupt changes in direction. The pipe 20 which extends tangentially away from the fan l2 leads tangentially into the upper end of the second separator I I, and this separator is adapted to remove the granular cooled material from the cooling air and to deliver the latter to the atmosphere through an upper cen-- tral outlet 30. The separated granular material is deposited by gravity toward the two-way chute 2| which is ordinarily provided with a swingable gate for effecting interchangeable delivery of the material to either outlet or spout of the chute. From the chute 2| the finally cooled granular material 22 may be delivered either into bags, or to a final disintegrator such as an impact pulverizer for further uniform reduction, and this final -disposition or treatment of the product is also old and well known.

While the normal operation of the improved system should be generallyv apparent from the foregoing description, I will again present a short rsum thereof. When the drier system is in operation, the drum 5 and the rotors of the fans 9, l2, are being constantly revolved, and the material admitted to the inlet end of the drier drum 5 is being transported through the revolving drum by hot air or gases and is being simultaneously agitated by the internal flights of the drum. The main fan 8 constantly withdraws the mixture of hot gases and material through the pipe 9 and delivers the mixture of material into the upper end of the main separator ll through the pipe I9. In the separator II the dry granular material is removed from the hot gases, the latter being discharged through the upper outlet 22 and the former being delivered by gravity through the open delivery end I of the cyclone separator and into the hopper l5. As the granular material 22 falls through the hopper i5, it entrains air from the ambient atmosphere and is initially cooled thereby. The auxiliary suction fan I2 is creating a relatively rapid flow of air into the open lower end I! of the conduit i3, and this entering cooling air upon striking the finer and lighter particles of material 22 passing through the outlet end ill of the hopper l5, carries these lighter particles upwardly through the pipe ii. The heavier particles 21, however, gravitate through the stream of cooling air which enters the pipe end l1, and drop upon the fioor 24 directly beyond the open inlet end of the pipe l3 as clearly shown in Fig. 2. when a screen 28 is used, this screen will catch larger particles of relatively light material and will retain the same, and the hopper i5 may occasionally be swung about its hinge 26 so as to permit removal of lodged material from the screen 28. Depending upon the setting of the shut-oil gate [8, the velocity of the stream passing through the pipe I 3 may be varied, to thereby vary quantity of heavier particles 21 which are discharged from the lower end I! of the pipe [3. When the gate I8 is fully open, there will be least obstruction to the flow. of air and solids to the fan l2, thereby separating only the heavier particles 21 from the mixture. If, however, the gate I8 is closed to a. considerable extent, a greater number of particles 21 will be separated from the finer particles, and the material may thus be graded. The mixture of fine material and cooling air which is sucked through the pipe i 3 by the fan I2, is delivered to the upper end of the secondary separator [9 through the pipe 20. In the separator 19, the'cooling air is removed and delivered through the outlet 30, while the cooled granular material 22 is deposited by gravity through the chute 2| either into bags or to the final disintegrator.

From the foregoing description it will be apparent that the present invention provides 'a simple and highly efllcient cooling and separating system ior quickly reducing the temperature of the product and for removing therefrom un- The relatively fine particles of the material 22 are subjected to cooling action both by the air entrained through the hopper l5 and by the abun- 1| dant quantities oi atmospheric air admitted through the open end I! oi the pipe II; and the velocity .within the pipe It may obviously be 'varied to suit diiierent conditions of operation. While the screen 28 may be desirable, this screen may obviously be omittedwithout impairing the usefulness oi the system, and the improved cooler and, separator has been found highly effective in actual commercial use.

It should be understood -that it is not desired to limit the present invention to the exact details of construction and to the precise mode of operation herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

desirably heaviergrades of material. The system ration may be conveniently varied at, any time.

I claim: a 1. In a system ior treating a mixture oi hot gas and granular material, a separator for removing the 'gas from the dry granular material and for delivering the latter into the ambient atmosphere, an upwardly inclined pipe having a laterally open lower end, a suction fan for producing a ilow of air into said open end and upwardly through said pipe, a. shut-oil gate in'said pipe upwardly beyond said open end, a hopper for delivering said granular material from the atmosphere downwardly into said pipe in advance oi said gate. and laterally beyond said open pipe end,

- and a screen spanning said pipe between said hopper and said gate. v

2. In a,cooling and separating system for hot granular material, an inclined pipe having an open lower end and a laterally upper inlet opening above the pipe bottom and directly adjacent said open end, means for creating a flow of air 20 into said open end and through said pipe beneath said opening, a hopper for delivering granular material from the atmosphere into said opening,

CHARLES WESLEY BOAG. 

